Control of electrically-operated switches.



v H. E. WHITE. CONTROL OF ELEGTRIGALLY OPERATED SWITCHES. APPLICATION FILED OGT.15, l910.

1,022,907. Patented Apr. 9, 1912.

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j? Z54 H F65 ATTUHNEY UNITED STATES PATENT OFFICE.

HAROLD E. WHITE, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CONTROL OF ELECTRICALLY-OPERATED SWITCHES.

Specification of Letters Patent.

Patented Apr. 9, 1912.

Application filed October 15, 1910. Serial No. 587,146.

To all whom it may concern:

Be it known that I, HAROLD E. WHITE, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in the Control of Electrically-Operated Switches, of which the following is a specification.

This invention relates to the operation of electrically controlled switches or contactors and particularly to switches, theoperation of which is controlled-by auxiliary switches or relays. I

One of the objects of my invention is to provide a system having an electrically operated switch under the control of a normally open relay, the arrangement being such that the controlling relay closes 'temporarily to actuate the main switch and immediately opens without affecting the switch. The closing of the relay may be under the control of the current in the main circuit so that the relay will not close if the current is excessive.

In another aspect my invention relates to a. system of control employing a plurality of contactors adapted to be successively closed to efiect certain desired connections in the starting of an electric motor. In the patent to A. S. Cubitt, No. 941,408, there is disclosed a. system of control of this character in which the contactors are successively controlled by a pair of relays which operate alternately so that by the alternate action of the two relays any desired number of contactors will be closed successively. In my present system I likewise employ a pair oi relays for controlling 'a series of con:- tactors. The relays in this case, however, are normally open and preferably mechanically supported in open position. The arrangement is such that the relays temporarily close to effect the closing of the con tactors and then immediately open. The closing of the relays is preferably under the control of the current in the motor circuit. The arrangement is such that as soon as a relay closes, .it actuates a contactor and at the same time short circuits the coil which holds the relay closed, thereby immediately o ening'the relay. These relays operating alternately cause the contactors to close successively. I

Other objects and purposes of my invention will appear in the course of the following specification, in which I have shown my invention embodied in concrete form for purposes of illustration.

Referring to the drawing, it will be seen that I have shown my invention in connection with the control of a three phase alternating current motor of the slip ring type, but it is obvious that my invention is in no sense limited to an alternating current system nor to the control of any particular type of motor.

In the drawings illustrating my inven tion, M represents a three phase induction motor supplied by alternating current mains 1, 9. and 3, through the switch 4.

R R represent sections of resistance in the secondary circuit of the motor which are adapted to be short circuited to bring the motor to running speed.

5, 6, 7 and 8 are electrically controlled switches or contactors adapted to be successively operated to short circuit the resistances R It. 1

i) and 10 are relays for controlling the actuation of the contactors.

The contactors are all similar in construction, consisting of the usual winding in a control circuit adapted to operate a pivoted switch arm or member 11 to close. itupon a corresponding switch contact 12. Each switch arm has an extension 13 on the opposite side of the pivot from the contact end. This extension has pivoted thereto a rod 14 carrying interlocking contacts 15,

16, 17 The succeeding contactors have interlocks 18, 19, 20, etc., contactor 8 being provided with only two of these interlocks. The arrangement is such thatwhen the contactor closes, the rod 14 is forced downward and certain interlocking connections are made. The relays 9 and 10, which control the contactors, are similarly constructed and consist of windings 9.1 and 22 in the control circuit having cores opera-ting pivoted arms 28 and 24, respectively, which normally support the respective rods 25 and 26 carrying contact members 27 and 28. Upon these rods 25 and 26 are cores surrounded by series windings which tend-to support them. The arrangement is such that when the windings 21 and 22 are energized the rods .25 and 26 will drop, providing the current in the series windings is not too high. When operates.

they do drop, however, each actuates one 'of the contactorsand at the same time short circuits the winding which by being energized allowed the rod to drop, so that the rods will be immediately lifted. In other words, the rods 25 and 26 are normally mechanically supported by the weight of the cores in the coils 21 and 22. When these coils are energized, the mechanical support is removed and the rods allowed to drop. As soon as a rod drops, the corresponding winding is deenergized and the support is again restored by the dropping of the core within the winding.

The arrangement of circuits and mode of operation of my system are as follows: Upon closing the main switch 4: and the control switch 29 the relay 10 will first be closed, the circuit being as follows: From phasel, conductor 80, winding 21, conductor 31, interlock 15, actuating winding of contactor 5 and back to phase Coil 21 is thus energized and lifts its core, thereby releasing the rod 25 which is allowed to drop when the current in the primary circuit is not excessive. Assuming the current to be normal, the rod 25 will drop, thereby short circuiting the coil 21 at contact member 27. The short circuiting of the winding 21 pro duces two results: It causes the rod 25 to be instantly raised and likewise permits the winding of contactor 5 to be sufficiently energized to close the contactor. The winding of thecontactor 5 is such that it will not operate its contactor when it is in series with the winding 21, but as soon as the winding 21 is short circuited, the contactor Contactor 5 is now actuated and cuts out a part of the resistance R It. When the contactor 5 closes, it opens its actuating' circuit of interlock 15 and completes a h lding circuit at interlock 16, so that the contactor will remain closed. The closing of contactor 5 likewise completes a circuit for the actuation of the relay 9 by energizing the winding 22 through the interlock 17, the circuit bein-gas follows: From phase 1, through conductor 30, winding 22, conductor 32, interlock 17, interlock 18, winding of contactor 6 back to phase 2. This energizes winding 22, releasing rod 26 and allowing it to drop, thereby short circuiting the winding 22. The short circuiting of winding 22 causes the rod 26 to be lifted and likewise causes the winding of contactor 6 to be sutlia circuit through the windingof contactor.

7 and winding 21. The relay 10 is thus once more energized to actuate the contactor 7 and the relay 9 is then again energized to actuate the contactor 8. The result is that the relay 10 first operates to actuate contactor 5; relay 9 then operates to actuate contactor 6 ,then relay 10 once more operates to actuate contactor 7 then relay 9 again operates to actuate contactor 8. The relays are closed alternately, for an instant, but will not close while the current is excessive.

It will be seen that I have provided a simple and etlicient arrangement for operating electrically controlled switches either singly or a plurality in succession.

It is obvious that my invention is in no sense limited to the particular system which I have shown, nor to the particular arrangement of circuits or construction of parts. an cept in so far as it is limited by the scope of the claims annexed hereto.

IV hat I claim as new and desire to secure by Letters Patent of the United States, is,

1. In combination, a plurality of contactors, and a pair of normally open relays arranged to temporarily close alternately to successively actuate said contactors.

2. In combination,'a plurality of contactors, a pair of relays mechanically supported in open position, and electrical means for temporarily releasing the relays alternately to cause them to close and actuate the contactors successively.

3. In combination, an electric motor, a plurality of contactors for controlling the same, and a pair of normally open relays arranged to temporarily close alternately under the control of motor current to suecessively actuate said contactors.

4. In combination, an electric motor, a plurality of contactors for controlling the same, a pair of relays mechanically support: ed in open position, and electrical means for temporarily releasing the relays alternately to cause them to close under the control of motor current to actuate the contactors successively.

5. In combination, a plurality of contactors, a control circuit, a pair of relays mechanically supported in open position, windings in the control circuit for releasing the relays alternately to cause them to close and actuate the successive contactors, and connections whereby the mechanical support of each relay is restored upon the closing of the relay.

6. In combination, an electric motor, a plurality'of contactors for controlling the same, a control circuit, a pair of relays mechanically supported in open position, windings in the control circuit for releasing the relays alternately under the control of motor current to cause them to close and actuate the successive contactors, and connections whereby the mechanical support of each relay is restored upon the closing of the relay.

e 7. In combination, an electric motor, a contactor for controlling the same, and a normally open relay arranged to temporarily close under the control of motor current to actuate said contractor.

S. In combination, an electric motor, a contactor for controlling the same, a relay mechanically supported in open position, a control circuit, and a winding in the control circuit for temporarily removing the support to permit the relay to close under the control of motor current to actuate said contactor. I i

9. In combination, an electric motor, a contactor for controlling the same, a relay mechanically supported in open position, a winding in series with the motor for controlling the closing of said relay, a control circuit, and a winding in the control circuit for temporarily removing the support to permit the relay to close under the control of motor current to actuate said contactor.

10. In combination, an electric motor, a contactor for controlling the same, a relay mechanically supported in open position, a control circuit, a winding in the'control circuit for removing the support to permit the relay to close under the control of motor current to actuate said contactor, and connections whereby the support is restored upon the closing of the relay.

11. In combination, an electric motor, a control circuit, a contactor having an actuating winding in the control circuit, a relay mechanically supported in open position, a winding in series with the cont-actor winding for removing the relay support to allow the relay to close, a winding in the motor circuit for retarding the closure, and connections whereby the closing of the relay short circuits the relay winding to increase the energy of the contactor winding and close the contactor.

12. In combination, an electric motor, a control circuit, a plurality of contactors having actuating windings in the control circuit, a pair of relays mechanically supported in open position, windings arranged to be alternately connected in series with the successive contactor windings to remove the supports and allow the relays to close, and connections wherebyl the closing of the relay short circuits t e relaywinding to restore the support and at the same time increase the energy of the contactor winding in series therewith and close the contactor.,

13. In combination, an electromagnetic switch, a relay for controlling the same, a member normally supporting the relay in open position, a winding for removin the supporting member, and connections w ereby said winding is deenergized upon the closing of the relay.

14. In combination, an electromagnetic switch having an actuating winding, a relay for controlling the same, a member normally supporting the relay in open position, a winding in series with said actuating winding for removing the supporting member, and connections whereby said winding is short circuited by the closing of the relay to close the electromagnetic switch and open the relay.

15. In combination, a plurality of contactors, a pair of actuating circuits leading to alternate contactors, and a normally open relay mechanism arranged to temporarily close and energize said actuating circuits alternately to successively actuate said con- I tactors.

16. In combination, a plurality of con tactors, a pair of actuating circuits leading to alternate contactors, and a relay mechanism mechanically supported in open position and arranged to temporarily close and energize said actuating circuits alternately to successively actuate said contactors.

17 In a relay mechanism, in combination, a switch member mechanically supported in open position, a winding arranged to be energized to remove said support and allow said switch member to close, and connections whereby the said winding is denergized upon the closing of the switch member to restore the support and open the switch.

18. In a relay mechanism, in combination, a switch member mechanically supported in open position, a winding arranged to be energized to remove said support and allow said switch member to close, means for controlling the closing of said switch member, and connections whereby the said windin is denergized upon the closing of sai switch member to restore the support and open the switch.

In witness whereof, I have hereunto set my hand this 14th day of October, 1910.

HAROLD E. WHITE.

Witnesses:

BENJAMIN B. HULL, HELEN Onrono. 

